The electrochemical and enzymatic oxidation of a variety of purine derivatives is being investigated. The electrochemical mechanistic information along with the analytical probes developed during this investigation is used to help unravel the mechanism of the enzymatic reactions. The systems under current investigation include purine bases such as uric acid and various N - alkylated uric acids, hypoxanthine, and xanthine and nucleosides such as uric acid -9- riboside, xanthosine, guanosine, deoxyguanosine, inosine, and 8-oxyguanosine.